Foundry flask with resilient for retaining band member



F eb. 24, 1959 FOUNDRY FLASK WITH RESILIENT FOR RETAINING BAND MEMBER Filed 001:. 5, 1956 R. J. HINES 2,874,425

2 Sheets-Sheet 1 INVENTOR. Russcu. J. Hines ATTORNEYS e-a... s

United States Patent FOUNDRY FLASK WITH RESILIENT FOR RETAINING BAND MEMBER Russell J. Hines, Lakewood, Ohio, assignor to The Hines glask Company, Cleveland, Ohio, a corporation of bio Application October 5, 1956, Serial No. 614,144

4 Claims. (Cl. 22-106) This invention relates to separable foundry flasks of the type having side and end walls interconnected at abutting ends to form a closed boundary for containing sand and more particularly relates to an improved means for retaining an endless band member within the flask whenever the same is in locked position.

In one of the methods used for making metal castings, a pattern plate is placed on the bed plate of a press, the plate having the cope forming portion of a pattern on the upper side thereof. A conventional foundry flask is then placed on the pattern plate in aligned relationship therewith. The flask may be rectangular in configuration and it may have side and end walls having a hinged interconnection at one corner and a separable interconnection at a diagonally opposite corner to permit its subsequent removal from a sand mold formed within it. An end-- less band member having the same configuration as the flask is then telescoped into the flask. The band functions as a reinforcingmeans for the completed mold during the pouring operation. Sand is then blown into the flask under high pneumatic pressure, after which the sand and the band undergo a squeezing operation, wherein, a press head (having a drag forming portion on its under side) is forced down onto the top surface of the sand until the top of the band is flush with the top of the sand and preferably is disposed slightly above the top of the flask, thereby forming the mold. Thereafter, the filled task is transported'to a pouring station and the flask is removed from the mold. The operation of flask filling, band inserting, and the squeezing operation are repeated, whereupon a second mold section is superimposed upon the first, the flask being removed and in the case of stack molding, the operation is repeated until a desired number of molds suitable for pouring is obtained. In each mold, the band remains embedded within the mold after the flask is removed, and provides a reinforcement against bursting of the mold upon the introduction of molten metal thereto.

In the above method, difficulty has been experienced in suspending the band in position within the flask above the bottom thereof during the sand blowing operation. The band is held in position by a tight metal-to-metal engagement with the inner walls of the flask and, although initially the band may fit into the flask with suflicient tightness to prevent its displacement during the sand blowing operation, after these parts have been used to make a few molds, they become heated unevenly and expand to different extents, with the result that the band eventually fits loosely within the flask. The problem is intensified by the fact that the band and flask are usually formed of different metals having different coefficients of expansion.

It is an object of the present invention to provide a foundry flask having means for preventing the displacement of an endless band member placed within the flask under all conditions of molding operations.

Another object of the invention is to provide a foundry flask having means for releasably securing a band memher in position within the flask during the mold making operation.

Briefly, the foregoing objects are accomplished by the provision of a foundry flask having side and end walls joined to define an enclosed foundry open at the top and bottom. The flask may have separable interconnections in the form of a releasable lock mechanism at diagonally opposite corners or a separable interconnection at one corner and a hinged interconnection at a diagonally opposite corner. The flask is adapted to receive an endless band member in tight telescopic engagement with the inner surface of the flask walls. The band member is of the same configuration as the flask and functions as a reinforcing means for the finished sand mold.

To retain the band securely in position within the flask,

resilient corner inserts are provided in at least two of theinside corners of the flask. In the preferred form, the inserts may be made of rubber and are L-shaped to conform to the configuration of the corner and may be secured in the corner by any suitable means such as bonding. Although the inserts may be disposed in all the inside corners of the flask, the band will be retained in position adequately with inserts positioned in one pair of diagonally opposite corners only. The band may be positioned within the flask by releasing at least one of v Other objects and advantages of the invention will be apparent from the following description taken in conjunction with the accompanying drawings in which:

Fig. l is a perspective view of a foundry flask made in accordance with the present invention and showing the band member positioned within the flask;

Fig. 2 is a top sectional view taken along the line 2-2 of Fig. 1;

Fig. 3 is a view similar to Fig. 2, but showing the flask lock mechanisms in released position;

'Fig. 4 is a perspective view of the band member; and

Fig. 5 is a side elevational sectional view taken along the line 5-5 of Fig. 3, but with the band member removed.

Referring to Figs. 1 and 2, there is shown a flask F which comprises side Walls 10 and 11 and end walls 12 and 13, disposed in abutting end-to-end relation to form a rectangular frame which is open at the top and bottom and is adapted for receiving a mold making material such as sand therein. The walls are releasably interconnected at two diagonally opposite corners by the lock or latch mechanisms 15 and 16 (Fig. 2). However, the flask may have a hinged interconnection at one corner and a releasable lock mechanism at the diagonally opposite corner.

The flask F is adapted to receive an endless band member B in tight telescopic engagement with the inner surfaces of the flask walls. The band is of the same configuration as the flask and comprises the side walls 20 and 21(Fig. 4) and end walls 22 and 23 joined in endto-end relation to form a rectangular frame. After a sand mold is formed, the band remains embedded within the mold and functions as a reinforcing means to prevent the mold from bursting during the pouring operation.

In one of the steps of the mold making operation,

Patented Feb. 24, 1959 loose fit between'the flask and the band may be caused by a wearing of these parts or by the uneven expansion of the parts as they become heated (unevenly) during the mold making operation. In addition, the fact that the flask and band are usually made of diflerent metals intensifies the expansion problem.

To suspend the band B securely in position within the flask F, corner inserts or pads 25 are provided in at least two of the inside corners of the flask. The inserts may be made of rubber or any like resilient material and preferably have an L-shaped configuration to conform to the shape of the flask corner and may be secured in the corners by any suitable means such as bonding. Although the inserts may be disposed in all the inside corners of the flask, the band B will be retained in position adequately with inserts positioned in one pair of diagonally opposite corners only as shown in Figs. 1, 2 and 3.

To insert the band into the flask, the lock mechanisms 15 and 16 are released as shown in Fig. 3, thus opening the flask and thereby permitting the band B to be telescoped easily therein. After the band is in position, it may be locked in such position by locking the lock mechanisms l5 and 16 (Fig. 2). With this construction, the flask grips the band by means of the inserts 25 only. Any expansion or contraction of the band will be compensated for by the inserts, thereby assuring a tight interfit between the flask and band whenever the lock mechanisms are locked.

The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding any equivalents of the features shown or described or portions thereof.

I claim:

1. A molding flask having a plurality of vertical walls interconnected at the respective ends thereof to define an enclosed boundary and having a hinged interconnection at at least one corner thereof and a separable interconnection at at least one other corner thereof, said flask also having a resilient pad secured to the inside surface of at least two of the inside corners thereof for retaining an associated endless band member in position within the flask when the separable interconnection is locked.

2. A molding flask having vertical walls interconnected at the respective ends thereof to define an enclosed sand boundary and having a locking mechanism at at least two of the corners thereof to releasably interlock the abutting ends of the adjacent walls thereat, said flask also having resilient pads secured to the inside surface of at least two of the non-releasably interconnected corners for retaining a band member in position within the flask when the locking mechanisms are locked.

3. A molding flask constructed in accordance with claim 2 wherein said pads are bonded in the respective corners of the flask.

4. A molding flask for making sand molds having side and end walls joined in the form of a rectangle and having a hinged interconnection at one corner thereof and a releasable latch mechanism at a diagonally opposite corner for releasably interlocking the flask, said flask including L-shaped resilient pads secured to the inside surface of at least two diagonally opposite inner corners of the flask to hold an associated endless band member of the same configuration as the flask in position on the inner periphery of the flask when the same is in locked position.

References Cited in the file of this patent UNITED STATES PATENTS 

